The present invention relates to handling, carriage, and storage of heavy pairs of wheels connected by axles, such as railroad car wheelsets, and relates particularly to apparatus for use in storage and carriage of such pairs of wheels and that is compatible with the handling of intermodal cargo containers.
Railroad car wheels are permanently mounted on axles that extend beyond the wheels. Bearings are mounted on the outer ends of such axles. A pair of wheels, an associated axle, and the associated bearing assemblies are called a wheelset, and such a wheelset is usually handled as a unit. A wheelset for a railroad freight car usually has a weight in the range of roughly 2,400 pounds, for a pair of 33-inch wheels, to roughly 3,500 pounds for a pair of 38-inch wheels. Most railroad freight car wheels are 36-inch wheels, with 33-inch and 38-inch wheels being somewhat less common.
During normal use railroad car wheels may wear unevenly, requiring the wheels to be resurfaced to an acceptable profile and circularity. New wheelsets, wheelsets needing reworking, and wheelsets that have been reworked must be transported to or from car building or repair facilities.
The axial length of a wheelset for use on standard-gauge North American railroad track is up to about 89⅝ inches. This is greater than the interior width of a conventional ISO cargo container, so railcar wheelsets have not previously been carried in cargo containers with the axles oriented parallel with the width of such a container, although handling a container carrying a group of wheelsets in a single operation would be preferred. Instead, wheelsets have usually been loaded individually onto a flatbed highway trailer or a railroad flatcar for transport, with the axles aligned perpendicular to the direction of travel. The wheelsets have usually had to be handled and secured individually to keep them properly in place. Securing wheelsets for carriage in that way requires personnel to be on a flatcar or trailer while it is being loaded, although this procedure risks serious injury to such personnel. In case of a collision involving the truck or flatcar carrying wheelsets in this manner the wheelsets have been likely to break loose and roll about uncontrollably.
To utilize available space economically on a flatcar or trailer wheelsets have been carried in staggered arrangements, with adjacent wheelsets offset from each other axially of the wheelsets, in alternating directions. Such arrangements, however, risk damage to a bearing assembly of a wheelset, which may be struck by a wheel of an adjacent wheelset as it is moved by a crane during loading or unloading of a flatcar or trailer.
In order to keep a trailer or railcar available for transporting other loads, wheelsets have been unloaded from the flatcar or trailer for storage at a facility where the wheels are to be reworked or are to be installed on a railroad car. This has required each wheelset again to be handled individually, resulting in significant associated costs for labor and the use of cranes or other handling equipment, and requiring allocation of space for temporary storage of wheelsets, as well as later handling of wheelsets one-by-one when they are to be reworked or installed.
Specially-equipped railcars for carrying wheelsets have included sets of rails on which wheelsets can be carried, either aligned with each other or in staggered arrangements, as shown in U.S. Pat. No. 1,626,709, but such railcars have not been widely used, and wheelsets have still had to be secured individually on such railcars and are still susceptible to rolling off in case of a collision that causes the railcar to be stopped abruptly.
What is needed, then, is a way to handle, carry, and store railroad car wheelsets more safely and economically than has previously been possible. It is also desirable to be able to carry and store such wheelsets in apparatus that is compatible with handling, storage, and transport of intermodal cargo containers.